Details

I upgraded to build 30609 in the last few days. After powering up, the Rockbox logo displays, then the screen goes dark & the unit powers down. It will then not respond to subsequent attempts to power up until connected to USB, at which point it can boot normally into the stock firmware.

This behavior occurred in 30614 as well.

I have worked around this problem by reverting back to a known good previous build, 30400.

there was a previous task here on flyspray. http://www.rockbox.org/tracker/task/12292 - it was supposedly fixed and the task was closed with r30613. but the fix only appears to work on the clip+. i have one myself and that is working again after exhibiting the same problem but my clip v2 still does not work.

For me, on the clipv1,
SVN r30588 works,
SVN r30589 ("FS#12273 - use buflib for font storage. thanks to the testers :)") did work at some point, hangs when trying again.
SVN r30590 ("fix the build errors") hangs

unfortunately that patch doesn't do anything for my clip v2. i get the splash and then the screen goes black exactly as before. i have to hard power off for 20 seconds or so to reset it. it's absolutely fine back on 30588 - and yes, i've been making sure the folder is clean with each test. :P